Andrew Lohmann

Comparitve performance of NFC coil reference designs

Discussion created by Andrew Lohmann on Aug 8, 2017

This is a follow up question to my question elsewhere on obtaining a Coil footprint used in a reference design -

  • IC to be used; M24LRxx but M24SRxx could be used.


Which of the 14x14mm or 15x15mm square designs has the longest range in passive mode lowest data rate?

  1. There are two examples of one design that has the coil on one side and no extra capacitors required.
  2. There are two examples of one design that has two coils one on each of two layers plus an extra 23pF loading. This design has a strange 0V strategy.


  • COMMENT on (2); I guess if a board with many layers were constructed the coils could be placed on an outer and the next nearest inner layer to reduce this extra capacitance required. But from the size of the capacitors it looks like another layer of coil would also mitigate some of the extra capacitance required and that could increase the power harvested?


Is there any information on the relative performance of each of the many example coils that ST offer?